The invention relates to a magnetic card read operated by a card carrying magnetic data. Such data may be authorization data, e.g. for use with a self-service financial terminal such as an automated teller machine (ATM), or may be data on a magnetic stripe `Smart Card` or electronic purse.
An advantage of such a card is the ease with which magnetic data can be written to the card, usually in a magnetic stripe, but unfortunately the converse is also true, and the data is easy to erase. Such an erasure can occur when the card is placed in close proximity to the magnetic clasp frequently used on handbags and pocket books. The damage may initially be slight, so that the card remains usable, but repeated exposure may cause cumulative damage and eventually the magnetic data will be unreadable. The card will then have to be replaced.